1. Field of the Invention
The present invention relates generally to an exercise apparatus. Certain embodiments relate to variable motion exercise apparatus that may allow exercise such as simulated climbing, walking, striding, and/or jogging.
2. Description of Related Art
Exercise devices have been in use for years. Some typical exercise devices that simulate walking or jogging include cross country ski machines, elliptical motion machines, and pendulum motion machines.
Elliptical motion exercise apparatus in many cases provide inertia that assists in direction change of the pedals, making the exercise smooth and comfortable (e.g., see U.S. Pat. Nos. 5,242,343 to Miller; 5,383,829 to Miller; 5,518,473 to Miller; 5,755,642 to Miller; 5,577,985 to Miller; 5,611,756 to Miller; 5,911,649 to Miller; 6,045,487 to Miller; 6,398,695 to Miller; 5,913,751 to Eschenbach; 5,916,064 to Eschenbach; 5,921,894 to Eschenbach; 5,993,359 to Eschenbach; 6,024,676 to Eschenbach; 6,042,512 to Eschenbach; 6,045,488 to Eschenbach; 6,077,196 to Eschenbach; 6,077,198 to Eschenbach; 6,090,013 to Eschenbach; 6,090,014 to Eschenbach; 6,142,915 to Eschenbach; 6,168,552 to Eschenbach; 6,210,305 to Eschenbach; 6,361,476 to Eschenbach; 6,409,632 to Eschenbach; 6,422,976 to Eschenbach; 6,422,977 to Eschenbach; 6,436,007 to Eschenbach; 6,440,042 to Eschenbach; 6,482,132 to Eschenbach; and 6,612,969 to Eschenbach).
Elliptical motion exercise apparatus are also described in U.S. Pat. Nos. 5,573,480 to Rodgers, Jr.; 5,683,333 to Rodgers, Jr.; 5,738,614 to Rodgers, Jr.; 5,924,962 to Rodgers, Jr.; 5,938,567 to Rodgers, Jr.; 5,549,526 to Rodgers, Jr.; 5,593,371 to Rodgers, Jr.; 5,595,553 to Rodgers, Jr.; 5,637,058 to Rodgers, Jr.; 5,772,558 to Rodgers, Jr.; 5,540,637 to Rodgers, Jr.; 5,593,372 to Rodgers, Jr.; 5,766,113 to Rodgers, Jr.; 5,813,949 to Rodgers, Jr.; 5,690,589 to Rodgers, Jr.; 5,743,834 to Rodgers, Jr.; 5,611,758 to Rodgers, Jr.; 5,653,662 to Rodgers, Jr.; and 5,989,163 to Rodgers, Jr., each of which is incorporated by reference as if fully set forth herein.
In many exercise apparatus, rigid coupling to a crank generally confines the elliptical path to a fixed stride or path length. The fixed elliptical path length may either be too long for shorter users or too short for taller users.
Adjustable stride elliptical exercise apparatus have been disclosed in previous patents (e.g., U.S. Pat. No. 5,743,834 to Rodgers, Jr.). Although some of these exercise apparatus have addressed the issue of a fixed path length, the stride adjustment is made through changes or adjustments to the crank geometry. Mechanisms for adjustment in such apparatus may add significant cost, may require input by a user to a control system, and/or may not react relatively quickly to user input.
Pivoting foot pedal systems have been disclosed in previous patents (e.g., U.S. Pat. No. 5,690,589 to Rodgers, Jr.). Pivoting foot pedal systems may be configured such that the pivotal connection to the pedal is located above the pedal surface and a pendulum action may occur during pedal pivoting. This pendulum action may slightly increase the stride length. Such increases in stride length, however, are generally a small percentage of stride length and are not generally perceived by a user of the apparatus.
U.S. Pat. No. 6,689,019 to Ohrt et al., which is incorporated by reference as if fully set forth herein, discloses a user defined, dynamically variable stride exercise apparatus. A crank based system with a link that engages a roller at the end of a crank is disclosed. The link may have springs or cams to control and limit stride length. The cams, however, are placed away from the user. The resultant forces created by the cam are limited because the full weight of the user may not be applied to the cam. A housing to cover the crank and cam system may be large, thus adding to manufacturing cost. In addition, the overall length of the system may be relatively high.